Electrically active implantable medical devices such as pacemakers and cardioverter/defibrillators are well known in the art. Such implantable medical devices commonly and historically have been configured to be implanted within the patient some distance away from the heart of the patient. Pacemakers have traditionally been positioned in the musculature or other tissue of the patient's shoulder below the collar bone. Cardioverter/defibrillators are typically implanted either in the patient's side or, with recent advances in miniaturization, in the patient's shoulder. By utilizing transvenous leads to position electrodes within and in proximity of the heart, such implantable medical devices may be so positioned away from the heart and still be configured to treat cardiac conditions.
Because such implantable medical devices are positioned in the patient's shoulder or other relatively accessible location in the patient's body, implantation and explantation of such implantable medical devices may be relatively straight forward. In particular, because such implantable medical devices are both implanted at a relatively shallow depth and are of a size which is relatively easily manipulable for a medical professional, such implantable medical devices have not commonly required specialized tools for removal from the patient. Such devices may be relatively straightforwardly implanted in the patient by accessing the implantation location surgically, securing the device in the hands, placing the device in the implantation location, connecting the implantable medical device to the transvenous leads and surgically closing the implantation location.
Recently, however, miniaturization of implantable cardiac devices, particularly pacemakers, has allowed devices to be manufactured of a size small enough to permit implantation of the device within the heart of the patient or within other organs or parts of the body with similar space constraints, such as the epicardium, the pericardium, the lungs and the peripheral vascular system. Such developments may reduce the discomfort a patient may experience having an implantable medical device implanted at a relatively shallow depth in their shoulder and obviate the need for invasive transvenous leads. Pacemakers with these qualities may be referred to as leadless pacemakers. However, while the musculature and tissue of the shoulder may provide relatively easy physical access to a leadless pacemaker or other leadless implantable medical device, inserting and positioning the leadless pacemaker in the heart of the patient may make the leadless pacemaker considerably more challenging to physically access for implantation from the patient relative to a device positioned in the patient's shoulder.